REQUEST: Support for cross-platform SEA generation

[HayDegha0917]

Discussed in #89

^{Originally posted by HayDegha0917 April 3, 2024}
We have been using pkg for crating SEAs. One of the great features of pkg is its support for generating SEAs for a variety of target OSes (for example, create a Linux executable from a Windows workstation). It does not seem that NodeJS's SEA capability supports this. Is it possible to add as a feature?

[GabenGar]

Wouldn't it bloat the main NodeJS codebase and the distribution binary file? It will basically have to include O(n^2) instructions for all supported platform pairs.

[HayDegha0917]

@GabenGar I don't know how pkg does it, but they seem to manage. I assume they bring in the binary at runtime.

[GabenGar]

They did it by creating their own binaries which had to be constantly patched to keep up with upstream nodejs binary. Hence why it was unsustainable and therefore archived now.
Basically if there is no equivalent lib to libuv but for cross-platform compilation, then it's not going to become a part of nodejs.

[joyeecheung]

Currently, cross-platform SEA generation is possible (as in, if you download executables for different platforms from the official source, generate one blob using an executable of your current platform, and inject the same blob into executables of different platforms, it still works and there's not much preventing it from working) unless you use the code cache or snapshot options (as those are platform-specific). It's more or less an undocumented feature at this point. It has been reported that it works nodejs/node#52420 (comment) - the injection would be based on executable format which can be done on even a platform that don't typically run that format, and the preparation blob layout is mostly the same across platform (again, unless you use code cache or snapshot) modulo endianness differences.

[HayDegha0917]

So it's possible to use this feature but it's more or less an undocumented feature and has significant limitations.

This part is understood.

The request I filed is to make it user friendly and, at the minimum, better documented. It would also be nice to remove the requirement to have all the code in one file which, again, increases the barrier to usage.

It's the difference between a feature that sort of works and only for 10% of the user base and one that is extremely useful and adds value to your product. Beyond that comment, I can't pretend to know your priorities, deadlines, and resource contentions. But it's a bit disturbing that you will not even acknowledge the difficulty, to a semi-experienced user, of creating a single-executable application without a lot of effort.

[joyeecheung]

Node.js isn't a product of a particular company or organization, but a community-driven open source project.

I can't pretend to know your priorities, deadlines, and resource contentions.

I don't think there's anyone setting any priority, or deadline, or resource contention for SEA. When someones request a feature, some existing contributor might to have interest/time in the said feature and get it done, or no one steps up and it never happens. Generally what happens in community-driven open source projects is that if one really wants something and no one else is planning to get it done, they would try to send some PRs and get it done themselves. Most contributors of Node.js start their contribution this way.

[robertsLando]

Just for reference, pkg isn't die as I'm maintaining it in this fork: https://github.com/yao-pkg/pkg

Also the patching of nodejs is almost automatic now with some workflows on gh.

I'm keeping an eye on node-sea and hope to integrate it on pkg soon. IMO the missing piece in order to make it work with almost all projects right now is the VFS, I know there have been some discussion about it here but I don't think any progress have been made on nodejs side to provide those hooks, right?

ATM the best way to use sea is:

1. Use a tool like esbuild/bpkg/ncc to bundle all the code to a single file
2. Produce the bytecode of this file
3. Download all required target arch/os nodejs binaries
4. Inject the generated bytecode into each target binary

Optional: Assets management. This may require some tweak on code side in order to handle assets load when inside node sea application.

[robertsLando]

Added sea support with cross-compilation support based on @joyeecheung suggestion to pkg here: yao-pkg/pkg#110